Question

Which of the following constants can be added to x^2- 3x to form a perfect square trinomlal?

A. 2 1/4
B. 1 1/2
C. 4 1/2

Answer 1

A 21/4

Explanation:

When forming a perfect square trinomial you need to "complete the square".

All of the steps to completing the square when solving an equation:

1. The leading coefficient must be 1.

2. Divide b by 2.

3. Square (b/2)

4. Add (b/2)^2 to both sides to keep the polynomial balanced.

5. You can now write the perfect square trinomial and solve.

x^2 - 3x

-3/2

(-3/2)^2 = 9/4 = 2 1/4